<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="https://cdn.bootcss.com/vue/2.6.10/vue.js"></script>
    <script src="https://cdn.bootcss.com/vue/2.6.10/vue.min.js"></script>
    <style>
        *{margin:0;padding:0}
        .bg {
            position: fixed;
            top: 0;
            bottom: 0;
            right: 0;
            left: 0;
            background: #333;
            display: flex;
            justify-content: center;
            align-items: center;
        }

        img.bg-img {
            width: 500px;
        }
        img.main-img{
            width:100%;
        }
    </style>
</head>

<body>
    <div id="app">
        <div>
            <img @click="handleClick" class="main-img" src="images/aboutus_banner.jpg" alt="">
            <div @click="handleBg" class="bg" v-if="isBg">
                <img class="bg-img" src="images/aboutus_banner.jpg" alt="">
            </div>
        </div>
    </div>
    <script>
        new Vue({
            el:"#app",
            data(){
                return{
                    isBg:false
                }
                methods:{
                }
            }
        })
    </script>
</body>

</html>